Now Lukaku, who signed for £13million rising to £18m, has revealed how he has “learned nothing” in his first year at Stamford Bridge and would gladly accept a loan move to another club.

This second attack will come as a bitter blow to interim boss Roberto Di Matteo or the new manager if Di Matteo is not kept on as the club tries to attract big names, including Lukaku’s fellow Belgian Eden Hazard.

Lukaku, who did not make the Champions League squad and was frozen out of the FA Cup run, was the hot property of last summer.

He was snared by then-Blues boss Andre Villas-Boas and taken to Stamford Bridge, where the 18-year-old claims his spirit was broken.

He said: “I will never forgive the previous coach what he did to me and took away.

“Not only because I was not on the European list, but just how he spoke to me and treated me.”

All smiles: Romelu Lukaku on the day he signed for Chelsea (Image: Getty)

The former Anderlecht star has revealed he watched the Champions League celebrations on Saturday night in Munich from the stands as he felt he had not contributed to the victory over Bayern.

He added: “We got to the final but I didn’t earn it. I would have had difficulty accepting a medal.

“I’ve not even touched the cup. I don’t deserve it because I was not on the list. I don’t touch anything I don’t deserve.

“That’s why I also didn’t touch the FA Cup.”

Lukaku is more optimistic about his prospects under Di Matteo but says he had informed the club that he wants to know that things will change from Villas-Boas’ days or he would like to explore other options.

He said: “In training, he put me on the right or left wing. In training matches, I was a substitute with a shirt to keep swapping teams. I really learned nothing!

“I have told the club that too. I understand that he was under pressure, but I was also thinking of myself. I have improved in recent months.

“In early July I go with Chelsea on tour to the United States.

“If the opportunities are fairly shared, I am sure Chelsea can convince me to stay. But I keep a loan still in my mind, the chances are fifty-fifty.”

"I will never forgive him": Lukaku is furious at former boss Andre Villas-Boas

Things turned sour for Lukaku after he signed a five-year deal last summer to play for AVB.

He said: “Right from the beginning, it was weird. I could not stand how he was treating me and I received no explanation.”

Lukaku’s first appearance for Chelsea came in the 83rd minute of the club’s League win over Norwich in August.

He was given 20 minutes at the end of the 3-1 League defeat to Manchester United two games later. He started the Carling Cup goalless draw at home to Fulham three days after that.

But after Chelsea’s run in that competition ended at the hands of Liverpool in January there were only brief cameos in one FA Cup tie and four Premier League games for Lukuku.

And although Villas-Boas vetoed January loan moves to West Ham, Stoke and a string of other Premier League clubs, Lukaku was still nowhere near his first-team plans.

The one Premier League game the frontman started was the meaningless 2-1 win over Blackburn on the final day of the season.

Two strikers - one nightmare

Romelu Lukaku signed for Chelsea last summer having been on Anderlecht’s books since he was 16.

He marked his 19th birthday on the final day of the season with his first start since November.

A precocious talent, he was named in the Belgium squad three months before he turned 17 and scored his first goals for the national side later that year.

Chelsea outbid a host of European clubs last summer but he struggled to impress manager Andre Villas-Boas. Even after AVB’s sacking, he rarely figured in Roberto Di Matteo’s plans.

Fernando Torres was signed for a British record £50million from Liverpool in January 2011. But the Spain striker had a nightmare start, failing to score in his first 13 games.

Four goals in his first full season were followed by a disastrous run of 24 games without finding the net.